Barrier movement operators generally comprise power and control systems for responding to operator inputs and sensed conditions. Operators thereby move barriers, such as garage doors or sliding gates, between open and closed positions. Various systems for operating and controlling movable barriers have been employed.
Though many movable barriers are now installed with operating systems, previously installed systems may be retrofitted to incorporate an operating and control system onto a movable barrier. In addition, if an installed barrier operator has failed, a new operating system may need to be incorporated onto a previously installed movable barrier. In general, such systems include a primary barrier control mechanism that couples with a corresponding barrier and causes the barrier to move (typically between closed and opened positions). One known approach to installing an operator includes removing the previously installed barrier or garage door from its mount and then install the operator that is mated to the barrier prior to remounting. Many conventional operators employ a sun gear with a central bearing that is configured to mount onto an end of an axle or shaft in either of what is known in the art as a live shaft or dead shaft configuration. In such configurations, the operator extends below the axle to accommodate a sun gear that rotates around the axle. Further, installation of such a movable barrier operator typically requires that the garage door be uninstalled so that the central bearing of the sun gear may be mounted onto the axle without interference from a bracket or other mounting structure. This, of course, can be cumbersome, error prone, and time consuming to accomplish, especially considering the size, weight, and shape of many movable barriers. Alternatively, some installers disconnect a portion of the barrier to avoid removing the entire mounted movable barrier from its mounted position. To that end, an installer may release one side of a mounted barrier, and may then rotate the barrier off a single side to partially remove a previously installed movable barrier. Such rotation and movement, however, may be dangerous due to the weight of the door and may also require specialized equipment.
In practice, though, some garage doors have been installed into spaces with little additional room to accommodate conventional operators. In such circumstances, even removing the movable barrier from the door mount may not permit an operator and controller to be installed into an insufficient space. Further, such space restrictions can, in fact, limit the use of operators for newly designed garage doors and openings where space is limited.
Conventional garage door operators such as rack and pinion drives or push-pull drive chain types are suitable for use in larger garage spaces which allow for hanger brackets to be connected from the ceiling to provide a rail for a drive chain that is connected to a trolley, which is movable along the rail. However, many garages, such as older garages, have relatively low ceilings and relatively little additional space to accommodate such conventional operators. In such circumstances, a shaft-mounted operator or jackshaft operator is often used to operate movement of the barrier. Jackshaft operators are suitable for use with garages having low ceilings or other space limitations as they do not require the additional center rail and trolley. One example of a jackshaft operation is described in U.S. Pat. No. RE40,001, which is incorporated by reference as through fully rewritten herein. A jackshaft operator typically has a motor with a motor housing and a control unit. The motor is operably connected to a jackshaft that is positioned parallel to an upper edge of the door and rotatably mounted above the garage door frame. A torsion spring may be wound around the jack shaft to provide a restoring force to it.
The jackshaft operator is typically mounted inside a parking structure or garage on a wall thereof immediately above the door opening and slightly offset, near a corner edge thereof. The jackshaft operator is operably connected to the jack shaft, which comprises a portion of the garage door structure and has a torque-providing helical spring wound thereabout for providing a restoring torque to the jackshaft. While such jackshaft operators occupy minimal space compared to operators having a rail and trolley configuration, some jackshaft operators still employs L-shaped tracks into which rollers attached to the garage door are permitted to ride, thereby guiding movement of the barrier from the open to closed position. The tracks may require additional installation and can be difficult for very small spaces to accommodate.
In addition, installing such an operator to a previously mounted garage door, as mentioned, can be quite difficult, especially considering the weight of a typical garage doors and barriers. For example, some operator configurations require that the previously mounted garage door be dismounted so that the operator can be positioned and properly mated with the garage door. Further, some garage doors have low ceilings and little additional room for a movable barrier operator that is significantly offset from the opening. For example, in a garage where the wall surrounding the opening adjoins another wall near that opening such that the space between the opening and the adjoining wall is limited.